Dynamic fiber optic switch

ABSTRACT

An apparatus and method of optical switching wherein a plurality of activation strips ( 18 ) are adhered longitudinally around an optical channel, such as an optical fiber ( 14 ) to cause the fiber to undulate in 2½ dimensions when the activation strips are activated. The activation strips are activated with a voltage source. By varying the polarity of the activation strip itself or the source used to activate the activation strip, the optical fiber can be caused to undulate by contraction and expansion of respective activation strips.

This application claims the benefit of the filing of U.S. ProvisionalPatent Application Ser. No. 60/121,778, entitled “Dynamic Fiber OpticSwitch and Fiber Optic Cable Switch,” filed on Feb. 26, 1999, and thespecification thereof is incorporated herein by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

A related application entitled “Dynamic Fiber Optic Switch withArtificial Muscle” is being filed concurrently herewith, to AlbertGoodman and Mohsen Shahinpoor, Attorney Docket No. UNM-540, and thespecification thereof is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention (Technical Field)

The present invention relates to fiber optic switches, particularly theuse of electro- or magneto-active materials to cause optical fibers toundulate.

2. Background Art

Present day optical fiber technologies are revolutionizing thetelecommunications industry. Tremendous advances have been made in thefield of telecommunications over the past decade. It has been estimatedthat this technology is capable of carrying tens of millions ofconversations simultaneously on a single optical fiber. Optical fibercommunication systems offer many advantages over systems that use copperwire or radio frequency links as a transmission medium. They includelower transmission losses, higher bandwidths, higher transmission rates,lower implementation costs, greater reliability and greater electricalisolation characteristics. It is clear that optical fiber communicationwill dominate the telecommunications industry in the very near futurebecause of advantages such as these.

Fiber optic switching is an important component in any telecommunicationsystem. These systems use switches to establish communication channelsamong two or more of their interfaces. An optical fiber switch iscapable of optically connecting, or aligning, any one of a first groupof optical fibers with any one of a second group of optical fibers, orvice versa, enabling an optical signal to propagate through the opticalinterface junction from one fiber to the other.

When two optical fibers are aligned end-to-end, light entering one fiber(the input or sending fiber) will continue into and through the secondfiber (the output or receiving fiber) while the two adjacent ends, orfaces, are aligned and close together. Fiber optic switches misalign ordisjoin the adjacent ends of the fibers by moving one or both of the twoends. By moving, for example, the first fiber's end to a new location,the signal, in this case light, can be redirected into another, thirdfiber, by aligning the first fiber's end with an end of the third fiber.

Lateral separation of the two adjacent ends will result in loss of lightbetween the two fibers so that a light absorber is provided beside thefiber which either moves into place as the receiving fiber moves away orstays in place as the sending fiber moves away. Space is provided forthis motion. This effectively switches the signal off. The discontinuitybetween the fiber ends may be either perpendicular to the fiber axis orat some angle to the axis but the gap is minimal when the fibers arealigned. Fibers may be collected into a bundle, a fiber optic cable,with a structure set up at the active location to permit the requiredmotion of a fiber end. A fiber bundle can be separated from a circularbundle cross-section to a linear arrangement where the fibers are in astraight line at the switch but reformed into a bundle again at thedevice exit.

Optical fiber switches generally utilize fiber positioning means,alignment signal emitter means and computer control means. Normally, afiber positioning means is provided near the end of one fiber toselectively point the end of that fiber in one fiber group toward theend of another fiber in the other fiber group to perform a switchedoptical transmission. Patents proposing to perform such switchingactions in fiber optic telecommunication systems include: U.S. Pat. No.5,024,497, to Jebens, entitled “Shape Memory Alloy Optical FiberSwitch,” which discusses switching activated by a shape memory alloywire in a transverse direction. U.S. Pat. No. 4,512,036, entitled“Piezoelectric Apparatus for Positioning Optical Fibers,” U.S. Pat. No.4,543,663, entitled “Piezoelectric Apparatus for Positioning OpticalFibers,” U.S. Pat. No. 4,651,343, entitled “Piezoelectric Apparatus forPositioning Optical Fibers,” and U.S. Pat. No. 5,524,153, entitled“Optical Fiber Switching System and Method Using Same,” all to Laor. usepiezoelectric bimorphs for positioning optical fiber switches. U.S. Pat.No. 4,303,302, to Rarrsey, et al., entitled “Piezoelectric OpticalSwitch” discusses other forms of piezoelectric bimorphs for opticalfiber switching.

Other patents discussing fiber optic switching include: U.S. Pat. No.5,812,711, to Glass, et al., entitled “Magnetostrictively TunableOptical Fiber Gratings;” U.S. Pat. No. 5,812,711 to Malcolm, et al.,entitled “Magnetostrictive Tunable Optical-Fiber Gratings;” U.S. Pat.No. 4,759,597, to Lamonde, entitled “Mechanical Switch for OpticalFibers;” U.S. Pat. No. 4,415,228, to Stanley, entitled “Optical FiberSwitch Apparatus;” U.S. Pat. No. 5,004,318, to Ohashi, entitled “SmallOptical Fiber Switch;” U.S. Pat. No. 4,844,577, to Ninnis, et al,entitled “Bimorph Electro Optic Light Modulator;” U.S. Pat. No.4,512,627, to Archer, et al., entitled “Optical Fiber Switch,Electromagnetic Actuating Apparatus with Permanent Magnet LatchControl;” U.S. Pat. No. 5,699,463, to Yang, et al., entitled “MechanicalFiber Optic Switch;” U.S. Pat. No. 5,841,912, to Mueller-Fiedler,entitled “Optical Switching Device;” U.S. Pat. No. 5,647,033, toLaughlin entitled “Apparatus for Switching Optical Signals and Method ofOperation;” U.S. Pat. No. 4,886,335, to Yanagawa, et al., entitled“Optical Fiber Switch System ” and U.S. Pat. No. 4,223,987, to Kummer,et al., entitled “Mechanical Optical Fiber Switching Device.” Thesepatents disclose various methods for fiber optic switching, includingmechanical devices such as rods, motors, and adapters, as well as waveguides and reflectors.

The Ohashi, Ramsey, Ninnis, Stanley, Jebens, Glass, and Laor patentsdisclose various methods and apparatuses that use piezoelectrics,magneto-strictive materials, and shape memory alloys, for bending thefiber; however, these patents are either complicated in theirconfigurations or require additional mechanical means beyond thesematerials. The present invention overcomes deficiencies in the prior artby directly adhering an electro- or magneto-active material to theoptical fiber, or fiber optic cable, itself, longitudinally to cause thefiber to undulate to the desired “2½-D” position, without additionalmeans of support or other mechanical means. The designation 2½-Dsignifies that the displacement of the fiber may produce both a lateraland a longitudinal change. The present invention is, therefore, a novelconfiguration for undulating an optical fiber or fiber optic cable.

SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)

The present invention is an optical switch comprising a plurality ofactivation strips adhered longitudinally around an optical channel tocause the channel to undulate in 2½ dimensions when the activationstrips are activated. Preferably, the plurality of the activation stripsare adhered longitudinally around an end of the optical channel to causethat end to undulate. The activation strips can be activated with asource that can vary in at least one of either amplitude, frequency, orpolarity. Each of the plurality of activation strips can be eithermagneto-strictive strips, piezoelectric strips, piezo-ceramic strips,piezo-polymeric strips, or shape-memory alloy strips.

Preferably, the activation strips are arranged symmetrically around thechannel. While two activation strips may be used, at least threeactivation strips are likewise arranged around the channel for a finerdegree of control of the direction of the displacement, or undulation.Alternatively, four activation strips can be arranged symmetricallyaround the channel wherein two of the four activation strips areoppositely polarized and located approximately 180° opposite oneanother, and the remaining two are oppositely polarized and locatedapproximately 180° opposite one another and located orthogonally to thefirst two.

The present invention is also an optical switch that is comprised of aninput having a plurality of input optical channels; a spherical segmentoutput having a plurality of output optical channels arrangedspherically around the input; and a plurality of activation stripsadhered longitudinally around the input optical channels to cause theinput optical channels to undulate in 2½ dimensions and align withdesired output optical channels when the activation strips areactivated. The activation strips can be adhered longitudinally around anend of each of the input optical channels to cause that end to undulate.The activation strips can be activated with a source that varies in atleast one of amplitude, frequency, or polarity. Each of the activationstrips can be either a magneto-strictive strip, a piezoelectric strip,piezoceramic strip, piezopolymeric strip, or a shape-memory alloy strip.Preferably, the activation strips are arranged symmetrically around theinput optical channels and at least three activation strips are used. Inan embodiment using four activation strips, two of the four activationstrips are oppositely polarized and located approximately 180° oppositeone another, and the remaining two are oppositely polarized and locatedapproximately 180° opposite one another and located orthogonally to thefirst two.

The present invention is further a method of switching optical channelsand comprises the steps of adhering a plurality of activation stripslongitudinally around an optical channel and activating the activationstrips to cause the channel to undulate in 2½ dimensions. Activating theactivation strips can comprise activating with a source that varies inat least one of amplitude, frequency, or polarity. Preferably, themethod specifically comprises the steps of providing at least one inputoptical channel with a first end and a second end, wherein the pluralityof activation strips are adhered longitudinally around the first endproviding at least two output optical channels arrayed within 2½dimensions of the first end of the at least one input optical channel;and activating the activation strips to cause the first end of the atleast one input optical channel to undulate in 2½ dimensions to alignwith one of the at least two output optical channels. Adhering theplurality of activation strips can comprise adhering at least twoactivation strips, wherein each of the activation strips can be either amagneto-strictive strip, a piezoelectric strip, a piezo-ceramic strip, apiezo-polymeric strip, or a shape-memory alloy strip. referably, themethod comprises arranging the activation strips symmetrically aroundthe channel, and comprises adhering at least three activation strips.Adhering at least three activation strips can comprise adhering fouractivation strips symmetrically around the channel; oppositelypolarizing two of the four activation strips and locating themapproximately 1800 opposite one another on the channel; and oppositelypolarizing the remaining two activation strips and locating themapproximately 180° opposite one another and orthogonal to the first two.

The present invention is further still a method of optical switchingcomprising providing an input having a plurality of input opticalchannel inputs; providing a spherical output having a plurality ofoutput optical channel outputs arranged spherically around the input;and adhering a plurality of activation strips longitudinally around theinput optical channels and activating the activation strips to cause theinput optical channels to undulate in 2½ dimensions and align withdesired output optical channels.

A primary object of the present invention is to provide an efficient andversatile means for switching an optical fiber or fiber optic cable byundulating the fiber, or cable.

Another object of the present invention is to undulate an optical fiberby placing electro-magneto-active material strips longitudinally alongthe optical fiber in order to move the optical fiber in 2½ dimensions.

A primary advantage of the present invention is that it does not requireadditional mechanical means beyond the electro- or magneto-activematerials adhered directly to the fiber.

Still another advantage of the present invention is that the opticalfiber can be moved in 2½ dimensions.

Other potential advantages provided by the present invention, due to itssimplicity and design, are long life, reliability, low cost, and avariety of applications.

Other objects, advantages and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or many be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The drawings are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention. In the drawings:

FIG. 1 is a cut-away view of the fiber optic switch of the presentinvention showing a single input fiber undulating between two outputfibers in accordance with the present invention;

FIG. 2 shows four activation strips adhered to an optical fiber inaccordance with the present invention;

FIG. 3 shows three activation strips adhered to an optical fiber inaccordance with the present invention;

FIG. 4 shows the fiber optic switch having one-fiber input andfour-fiber output capability in accordance with the present invention;

FIG. 5 shows a one fiber input and eight fiber output capability inaccordance with the present invention;

FIG. 6 shows a two fiber input and a spherical segment output having aplurality of fiber outputs in accordance with the present invention;

FIG. 7 shows a portion of an optical fiber having three activationstrips adhered along the portion of the fiber to be bent, as well as thevoltage supply to an activation strip;

FIGS. 8a and 8 b show a side view and cross-sectional view,respectively, of an optical fiber having two activation strips andelectrodes on two sides of each activation strip at the same end;

FIGS. 9a and 9 b show a side view and cross-sectional view,respectively, of an optical fiber having two activation strips andelectrodes on opposite ends of each activation strip; and

FIGS. 10a and 10 b show an optical fiber surrounded by amagneto-strictive material and having two electrodes opposite each otherat one end.

DESCRIPTION OF THE PREFERRED EMBODIMENTS BEST MODES FOR CARRYING OUT THEINVENTION

The present invention is a novel method and apparatus for optical fiberswitching which is based on adhering as part of the body of the fiberitself, electro- or magneto-active means in the form of wires and/orstrips adhered longitudinally to the fiber itself to quickly undulatethe end of a given optical fiber, from one group of fibers, to alignwith another optical fiber, from another group of optical fibers, in atelecommunication system. It is to be understood that the wordundulating, including other tenses and forms of that word, are hereinused to mean displacement and undulation of the fiber or fibers. Thepresent invention can either displace a fiber to a new position or causethe fiber to undulate back and forth between two or more positions asrequired in the application of the invention. The present inventionaccomplishes undulation in “2½-D.” In other words, the end of theoptical fiber to be moved is moved in both the x-axis and y-axisdirections, as well as somewhat in the z-axis direction necessarily dueto the bending of the fiber. The electro- or magneto-active meansinclude smart materials such as shape-memory alloys or polymer strips orwires, piezoelectric (piezoceramics, piezopolymers, etc.,) strips,magneto-strictive strips, and electro- or magneto-active polymers suchas ionic polymeric conductive composites (artificial muscles). Theelectro- or magneto-active means are referred to herein as “activationstrips.”

The fundamental principle is to extend an activation striplongitudinally along and adhered to an optical channel, be it an opticalfiber, a group of fibers, or a fiber optic cable. The activation stripcan be attached by cement, epoxy or glue between the activation stripand the fiber. Other bonding materials may also be used.

The present invention either switches an optical signal on or off, ordirects an optical signal into a variety of output optical fiberchannels. This is done by moving the end of an input fiber, or group offibers in a fiber cable, toward or away from the end of an output fiber,several output fibers, a group of fibers or several groups of fibers. Ofcourse, output fibers can additionally or alternatively be moved in thesame manner as described for the input fiber or fibers to provide otherswitching functions. It is to be understood that while the fibers to bemoved and having the activation strips are referred to as “input” fibersand those receiving the signal therefrom are “output” fibers, the signalcan of course travel in the opposite direction so that the output fiberor fibers become the input fiber or fibers and vice versa. The labelsinput and output are merely used for simplicity of explanation.

The switch provides on-off action by displacing the input and outputfibers by at least a complete fiber diameter. A partial light intensitychange may be accomplished by a controlled displacement distance. Adiagonal slice arrangement between the ends of the input and outputfibers will permit an intensity variation dependent upon separation ofthe two faces of the input and output fibers. Redirecting the opticalsignal is accomplished by undulating the end of the input fiber until itis aligned with the appropriate output: fiber or vice versa. Then, byhaving the faces of the ends of the input and output fiber to be joined,cut at diagonals to “fit” each other like two pieces in a puzzle, itallows the input fiber to “snap” into place against the receiving end ofthe output fiber and be more easily held there.

The displacement of a fiber is accomplished by the activation stripsadhered longitudinally to each fiber near the active end wheredisplacement or alignment is needed. Attention is now turned to thefigures. These figures are only to present examples of what can beaccomplished in accordance with the present invention.

FIG. 1 shows fiber optic switch 10 having input fiber 14 and outputfibers 16 and 16′. Channel guide 12 provides space in which input fiber14 can undulate. Input fiber 14 undulates in the area generally referredto as 20 and aligns with either output fiber 16 or 16′, thereforetransmitting the signal out of end 24 of switch 10 in the appropriatechannel. In this figure, two activation strips 18 and 18′ are shownadhered to input fiber 14. The operation of the activation strips isfurther described below.

FIG. 2 shows input fiber 14 having four activation strips 18, 18′, 18″,and 18′″, adhered along the length of input fiber 14 at 0°, 90°, 180°and 270° for a fine degree of control. FIG. 3 shows three activationstrips 18, 18′ and 18″ adhered along input fiber 14 at 0°, 120° and240°. Of course, any number of activation strips, preferably two ormore, can be adhered to input fiber 14 longitudinally at anycircumferential location in order to achieve the desired amount ofcontrol and fiber movement. While activation strips are shown adhered toan end of the input fiber, the invention is not limited to movement ofthe input fiber a one, but could of course include moving the outputfiber or fibers as well by the same method.

FIGS. 4 and 5 show fiber optic switch 10 with a single input fiber 14and a plurality of output fibers to which input fiber 14 can be alignedand transmit signal to. FIG. 6 shows an embodiment wherein a sphericalsegment. of output fibers is within the reach of input fibers. Inputfibers, such as 14 and 14′, are inserted into the hollow sphere 40 andundulate to the appropriate output fiber. Activation strips along theinput fibers cause these fibers to move to the desired output fiberlocation in order to transmit the signal in the appropriate direction.Sphere 40 may be a sphere segment, such as a hemisphere, or any otherdefined port on of a sphere, provided that the output fibers arearranged spherically about the axis of the input fiber or fibers.Furthermore, as described above regarding the designations “input” and“output,” in FIG. 6 fibers 14 and 14′ can constitute output fibers whilethe fibers shown at 24 constitute input fibers.

FIG. 7 is a blown-up view showing a portion of the fiber to becontrolled, whether it be input fiber 14 or any other fiber. Threeactivation strips are shown adhered along input fiber 14. While voltagesource 30 is shown connecting to activation strip 18″, it is to beunderstood that each activation strip requires its own voltage supplyfor activation. Each activation strip is coated by electrodes to whichactivation voltages are applied. Electrodes can be either thin metallicor conductive films such as carbon or graphite, or a thin wireconnection. These are easily attached by automated manufacturingprocesses known in the art. Piezoelectric materials require a highvoltage and low current because they are more or less non-conductorswhile shape-memory alloys require moderate voltage and current to heatthem, and require up to a few tens of volts and up to 1 or 2 amps ofcurrent. One target design voltage for activation is approximately 5volts with a maximum current of approximately 400 mA. This is a typicalvoltage and current compatible with computer voltages for computer anddata acquisition system integration. However, the voltages required maybe lower depending on the dimension of the fibers to be moved. Ingeneral, the smaller the fiber diameters the smaller the voltagerequired to activate and move the activation strip. Typically, for a 1mm diameter fiber to be moved at most 2 mm one would need a voltage ofabout 2 volts. Each activation strip 18 is comprised of an electro- ormagneto-active material as will now be described. While only twoactivation strips are discussed with reference to each embodiment, thisis, done for simplicity and it is to be understood that the inventionrequires at least two activation strips and most preferably requires atleast three activation strips, such as shown in FIG. 7, for the desired2½-D control. Either the polarity of the voltage or magnetic fieldsource, or the polarity of the electro- or magneto-strictive materialitself can be altered to effect expansion and contraction of thematerial as will be described next.

In a first embodiment, a plurality of magneto-strictive strips, such asTerfenol-D, approximately a few centimeters long, for example two cm,and of a width of a few microns are adhered in a symmetrical fashionlongitudinally to each fiber near the end to be undulated. Theseactivation strips are powered by an imposed magnetic field and eitherexpand or contract according to the polarity of the magnetic field. Themagnetic field is normally produced around a magneto-strictive materialby a coil arrangement. In this embodiment the coil is attached to orembedded in the activation strip and the coil is powered by a voltagesupply connected to each activation strip in the same way as describedbelow for other embodiments. By controlling the magnetic field appliedto each individual activation strip, the end of the optical fiberundulates dynamically and quickly to perform the switching function. Forexample, if two magneto-strictive strips are placed 180 degrees oppositeeach other longitudinally along the cylindrical mantle of a fiber, thenthe fiber can be made to move to either the left or the right byconcurrently expanding one magneto-strictive strip while contracting theother magneto-strictive strip. The degree of movement to the left or tothe right can be controlled by the amount of contraction or expansion ofeach of the magneto-strictive strips which is directly related to thestrength of the magnetic field applied to each strip. Of course,additional magneto-strictive strips are adhered along the length of thefiber for a finer degree of control of movement in 2½-D. Indeed, anentire sleeve or jacket of the material can envelop the fiber and iscontrolled by a plurality of electrodes upon the jacket. FIGS. 10a and10 b show a side view and a cross-sectional view, respectively, of thisembodiment. Jacket 50, which is comprised of a magneto-strictivematerial envelopes optical fiber 14. Electrodes 34 and 36 are powered byvoltage supply 30 which is controlled by switch 32. Upon closing switch32 and applying voltage to electrodes 34 and 36, a magnetic field isproduced around jacket 50 by one or more coils embedded in jacket 50.While only two electrodes are shown for simplicity in these figures,more electrodes and associated coils are used for a finer degree ofcontrol of movement.

In a second embodiment, a plurality of piezoelectric, piezoceramic, orpiezo-polymeric strips, such as lead zirconate titanate (PZT) orpolyvinylidine difluoride (PVDF), approximately a few centimeters long,such as two cm, and of a width of a few microns are adhered in asymmetrical fashion longitudinally to each fiber near the end to beundulated. Piezoelectric materials are electrostrictive in the sensethat if electrodes are attached to a strip having width, length andthickness, across the thickness and a voltage is applied, normally ahigh voltage of few 1000 volts, then they either contract or expandlengthwise. Piezoelectric materials expand or contract according to thepolarity of their properties and of the voltage applied to them. FIGS.8a and 8 b show a side view and a cross-sectional view, respectively, ofthe second embodiment of the present invention. In this embodiment,activation strips 18 and 18′ are adhered longitudinally along opticalfiber 14to be undulated. Voltage supplies 30 and 30′ controlled byswitches 32 and 32′ supply voltage to strips 18 and 18′ via positiveelectrodes 36 and 36′ and negative electrodes 34 and 34′ attached toeach strip. Due to the way that the voltage supplies are connected,strip 18 is polarized opposite strip 18′. By closing switches 32 and32′, the voltage is applied to strips 18 and 18′. Accordingly, strip 18contracts while strip 18′ expands, causing fiber 14 to bend in an upwarddirection as shown in FIG. 8a.

In a third embodiment, a plurality of shape-memory alloy wires orstrips, such as Nitinol, approximately a feN centimeters long, such astwo cm, and of a width of a few microns are adhered in a symmetricalfashion longitudinally to each fiber near the end to be undulated.Shape-memory alloys either contract or Expand due to a temperaturetransition from a solid phase of Martensite (crystalline structure isface-centered) to a solid phase of Austenite (crystalline structure isbody-centered) due to direct electric Joule heating of the material.Shape-memory alloys either contract or expand according to the polarityof a voltage applied to them. By controlling the amount of voltageapplied to each strip, the end of the optical fiber undulatesdynamically and quickly to perform the switching function. FIGS. 9a and9 b show a side view and a cross-sectional view, respectively, of thethird embodiment in its simplest form. Two activate on strips 18 and 18′are shown adhered 180 degrees opposite one another along the cylindricallength of optical fiber 14. Each activation strip 18 and 18′ iscontrolled by voltage supplies 30 and 30′, respectively. Switches 32 and32′ control the voltage supplied to the respective shape-memory wires.Positive electrodes 36 and 36′ are attached to activation strips 18 and18′, respectively, but at opposite ends. Negative electrodes 34 and 34′are attached at opposite ends from positive electrodes 36 and 36′ toactivation strips 18 and 18′. As demonstrated in FIG. 9a, by closingswitches 32 and 32′, voltage is applied to activation strips 18 and 18′causing strip 18 to contract and strip 18′ to expand. This is due to thefact that the voltage polarities across the two shape-memory strips areopposite. Because activation strip 18 contracts and activation strip 18′expands, and they are both directly adhered to optical fiber 14, opticalfiber 14 bends in an upward direction. Reversing the polarities of thevoltages applied to strips 18 and 18′ will cause the fiber to benddownward instead.

Of course, any optical channel, be it an optical fiber, a group offibers, or a fiber optic cable, can be moved in the same manners asdescribed above. Also, it is to be understood that the fiber can bemoved using combinations of the various activation strip materialsdescribed above. The activation strips are to be affixed to the input oroutput optical channels in accordance with the application for theswitch. While only one direction of motion is shown in FIGS. 8-10, and aparticular arrangement of electrodes and polarities is shown, it is tobe understood that any direction of movement can be accomplished byvarying locations of the activation strip or strips, polarities, andnumber of strips. In all of the embodiments presented, the voltage neednot be a constant voltage, but can of course be a variable voltagewaveform that varies in either frequency, amplitude, or polarity, or anycombination of those three so as to control undulation frequency of thefiber, fibers, or cable.

The present invention may be used in telecommunications for signalon-off control; signal routing from one destination to another; signalattenuation; signal combination by having two or more outgoing bundlesfrom two or more sources to be formed into a single bundle; and signalsplitting as to send a signal to more than one destination. Theinvention may be located at either the transmitting or receivingterminals of a communication channel or any intermediate location. Aswith any electromechanical device, the functioning bandwidth of theundulation frequency of the switch spans a fraction of Hz to an upperlimit of a few kilo Hz.

Although the invention has been described in detail with particularreference to these preferred embodiments, other embodiments can achievethe same results. Variations and modifications of the present inventionwill be obvious to those skilled in the art and it is intended to coverin the appended claims all such modifications and equivalents. Theentire disclosures of all references, applications, patents, andpublications cited above are hereby incorporated by reference.

What is claimed is:
 1. An optical switch comprising an input comprisingat least one input optical channel; an output comprising at least oneoutput optical channel; and a plurality of activation strips adheredlongitudinally around each of said at least one input optical channelsto cause said at least one input optical channel to undulate in 2½dimensions and align with the desired output optical channel when saidactivation strips are activated.
 2. The switch of claim 1 wherein saidplurality of activation strips are adhered longitudinally around an endof said at least one input optical channel.
 3. The switch of claim 1wherein said activation strips are activated with a source that variesin at least one of amplitude, frequency, or polarity.
 4. The switch ofclaim 1 wherein said plurality of activation strips comprises at leasttwo activation strips selected from the group consisting ofmagneto-strictive strips, piezoelectric strips, piezoceramic strips,piezo-polymeric strips, and shape-memory alloy strips.
 5. The switch ofclaim 1 wherein said plurality of activation strips are further arrangedsymmetrically around said at least one input optical channel.
 6. Theswitch of claim 5 wherein said plurality of activation strips comprisesat least three activation strips arranged symmetrically around said atleast one input optical channel.
 7. The switch of claim 6 wherein saidat least three activation strips comprises four activation strips, andwherein two of said four activation strips are oppositely polarized andlocated approximately 180 degrees opposite one another, and theremaining two are oppositely polarized and located approximately 180degrees opposite one another and orthogonal to the first two.
 8. Anoptical switch comprised of: an input having a plurality of inputoptical channels; a spherical segment output having a plurality ofoutput optical channels arranged spherically around said input; and aplurality of activation strips adhered longitudinally around said inputoptical channels to cause said input optical channels to undulate in 2½dimensions and align with the desired output optical channels when saidactivation strips are activated.
 9. The switch of claim 8 wherein saidplurality of activation strips are adhered longitudinally around an endof each of said input optical channels to cause that end to undulate.10. The switch of claim 8 wherein said plurality of activation stripsare activated with a source that varies in at least one of amplitude,frequency, or polarity.
 11. The switch of claim 8 wherein said pluralityof activation strips comprises at least two activation strips selectedfrom the group consisting of magneto-strictive strips, piezoelectricstrips, piezoceramic strips, piezo-polymeric strips, and shape-memoryalloy strips.
 12. The switch of claim 8 wherein said plurality ofactivation strips are further arranged symmetrically around said inputoptical channels.
 13. The switch of claim 12 wherein said plurality ofactivation strips comprises at least three activation strips arrangedsymmetrically around said input optical channels.
 14. The switch ofclaim 13 wherein said at least three activation strips comprises fouractivation strips, and wherein two of said four activation strips areoppositely polarized and located approximately 180 degrees opposite oneanother, and the remaining two are oppositely polarized and locatedapproximately 180 degrees opposite one another and orthogonal to thefirst two.
 15. A method of switching optical channels, the methodcomprising the steps of adhering a plurality of activation stripslongitudinally around an optical channel and activating the activationstrips to cause the channel to undulate in 2½ dimensions.
 16. The methodof claim 15 wherein the step of activating the activation stripscomprises activating the activation strips with a source that varies inat least one of amplitude, frequency, or polarity.
 17. The method ofclaim 15 wherein the step of adhering a plurality of activation stripscomprises: a) providing at least one input optical channel with a firstend and a second end, wherein the plurality of activation strips areadhered longitudinally around the first end; b) providing at least twooutput optical channels arrayed within 2½ dimensions of the first end ofthe at least one input optical channel; and wherein the step ofactivating the activation strips comprises: c) activating the activationstrips to cause the first end of the at least one input optical channelto undulate in 2½ dimensions to align with one of the at least twooutput optical channels.
 18. The method of claim 15 wherein adhering aplurality of activation strips longitudinally around an optical channelcomprises adhering at least two activation strips selected from thegroup consisting of magneto-strictive strips, piezoelectric strips,piezoceramic strips, piezo-polymeric strips, and shape-memory alloystrips around an optical channel.
 19. The method of claim 15 whereinadhering a plurality of activation strips longitudinally around anoptical channel further comprises arranging the activation stripssymmetrically around the channel.
 20. The method of claim 19 whereinadhering a plurality of activation strips comprises adhering at leastthree activation strips arranged symmetrically around the channel. 21.The method of claim 20 wherein adhering at least three activation stripscomprises: a) adhering four activation strips symmetrically around thechannel; b) oppositely polarizing two of the four activation strips andlocating them approximately 180 degrees opposite one another on thechannel; and c) oppositely polarizing the remaining two activationstrips and locating them approximately 180 degrees opposite one anotherand orthogonal to the first two.
 22. A method of optical switching, themethod comprising the steps of: a) providing an input having a pluralityof input optical channels; b) providing a spherical segment outputhaving a plurality of output optical channels arranged sphericallyaround the input; and c) adhering a plurality of activation stripslongitudinally around the input optical channels and activating theactivation strips to cause the input optical channels to undulate in 2½dimensions and align with desired output optical channels.